It is known that chest drainage consists in applying, after surgery or trauma, a tube which is connected to the chest cavity of a patient in order to allow exuded liquids and air losses to be conveyed to an appropriate apparatus.
While the exuded liquids are collected within such apparatus, the air losses, if present, are currently made to pass, before being evacuated from the apparatus, through a device which indeed indicates their presence by utilizing the bubbling of air bubbles within a vessel filled with liquid, usually water or physiological solution.
A device which is particularly widespread in the background art has, for example, a plurality of bubbling ports which are arranged at different distances from where any air losses arrive in the liquid, and this device is capable of providing qualitative information regarding the behavior over time of the extent of such losses by observing the number of ports affected by the phenomenon.
All currently known devices of the physical type provide, as seen for the one mentioned above, simply qualitative and instantaneous indications regarding the presence of any air losses, but today it has become important, as a consequence of research that medicine is conducting in this field, to know precisely the value of the flow-rate of such losses.